Need ideas for structuring deals with a cash only partner!?!

Hey gang! I have acquired 14 rental units over the past 12mos, and am currently knee deep in 3 flips in order to generate more capital (to purchase more rental property). So to do more deals now, I have a family member that is very game and interested in lending cash, and there are a few deals I am eye balling right now. What I need help with, is a couple of good ideas how to set up and structure deal, when essentially party A (myself) is finding, buying,  and managing the property. And party B (family member) is simply providing cash and looking for a return. Generally, I am looking to buy and hold for the long term. Any resources, ideas, books, articles etc on how to structure this would be super appreciated!!